Discover soil最新文献

{"title":"Forest harvesting alters the biogeochemical character and protection of mineral associated carbon in a Podzolic soil.","authors":"S MacIntyre, L Kellman, C E Gabriel, A Diochon","doi":"10.1007/s44378-026-00261-6","DOIUrl":"10.1007/s44378-026-00261-6","url":null,"abstract":"<p><p>Forest harvesting can alter the biogeochemical processes that determine the quantity and chemical nature of stored soil organic carbon (SOC). This SOC is distributed amongst organic compounds in soils of varying biological and physical complexity, with a large fraction of this SOC associated with metals and minerals. The objective of this study was to investigate changes in fractions of SOC associated with metals and minerals and their chemical character through depth and time for Podzolic soils of a harvested temperate red spruce (<i>Picea rubens</i> Sarg.) forest chronosequence to understand biogeochemical changes in SOC and its sensitivity to forest harvesting disturbance. A standard analytical approach was used to sequentially extract C from mineral pools of increasing SOC retention strength through depth (0-5, 5-10, 10-15, 15-20, 20-35, 35-50 cm) and time (1, 15, 45, 80, and 125⁺-yr) following forest harvesting. The biogeochemical character of the largest pool was assessed using aromaticity (specific UV absorbance: SUVA₂₅₄) and stable C-isotopes (δ¹³C). Results show that the organo-metal complexed fraction accounted for the largest pool examined (~ 59-85% of mineral associated SOC) and was most susceptible to harvesting losses, particularly in the deeper mineral soil. Biogeochemical patterns of SOC within this pool through depth showed distinct changes including: i) a lower aromaticity with lower C content across all sites within the deep mineral soil (20-50 cm), and ii), a correlation between decreases in aromaticity and increases in δ¹³C across all sites. This pattern of lower aromaticity and enriched δ¹³C can be interpreted as a shift towards more microbially processed and/or simpler compounds. Overall, the observed patterns support the conceptual hypothesis that forest harvesting alters the biogeochemical character and protection of the mineral associated fraction of SOC in soils of this region.</p>","PeriodicalId":520462,"journal":{"name":"Discover soil","volume":"3 1","pages":"118"},"PeriodicalIF":0.0,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13368850/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148458359","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Amendment-driven changes in nutrient availability and forage uptake in a recently converted boreal soil.","authors":"Aman Dhindsa, Adrian Unc, Amana Jemal Kedir, Maren Oelbermann","doi":"10.1007/s44378-026-00318-6","DOIUrl":"10.1007/s44378-026-00318-6","url":null,"abstract":"<p><p>Climate change and concerns over regional food security and sovereignty are accelerating the expansion of land-based agriculture into northern boreal regions. This requires tailored solutions to overcome the severe fertility constraints of recently converted Podzolic soils. Organic matter additions and liming agents have been proposed as rapid-solution soil amendments due to their capacity to reduce soil acidity, mediate nutrient availability and uptake, and improve crop nutrient use efficiencies. A randomized complete block design field trial was established in Central Labrador, Canada, from May to September 2023, the first-year post-conversion from forest to agriculture. Treatments included: mineral fertilizer (300 kg/ha 20:10:5 N:P:K + 176 kg/ha potash) or fish meal (1,075 kg/ha), as nutrient sources; biochar (20.8 Mg C/ha), peat (25.1 Mg C/ha), or peat with limestone (25.1 Mg C/ha peat + 5,400 kg/ha limestone), as organic matter inputs / liming agents; and monocrop oat, pea, and oat-pea intercrop, as cropping systems. All 36 treatment combinations were replicated across three blocks. Biochar-amended and peat with limestone-amended plots produced the highest forage crop aboveground biomass, nutrient (N, P, K) uptakes, and use efficiencies (<i>p</i> < 0.05). Treatments that increased soil pH and nutrient supply had immediate positive effects on soil fertility parameters in this sandy acidic Podzolic soil. Biochar, as well as peat with limestone, provided immediate alleviation of Podzolic fertility constraints (low pH, low CEC, poor organic matter functionality) in the first-year post-conversion, enabling oat and pea crop production before long-term soil organic matter accumulation can develop.</p><p><strong>Supplementary information: </strong>The online version contains supplementary material available at https://doi.org/10.1007/s44378-026-00318-6.</p>","PeriodicalId":520462,"journal":{"name":"Discover soil","volume":"3 1","pages":"179"},"PeriodicalIF":0.0,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13642377/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149130067","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Land conversion from forest to agriculture redistributes but does not reduce soil organic carbon stores in northeastern Ontario, Canada.","authors":"Bayze Murray, Amanda Diochon","doi":"10.1007/s44378-026-00207-y","DOIUrl":"10.1007/s44378-026-00207-y","url":null,"abstract":"<p><p>Climate change is creating conditions for agriculture to expand northward. For conventional large-scale operations, this will require the conversion of forests to agricultural land in most areas, which has historically been associated with large (30%) losses of soil organic carbon (SOC) and soil degradation. To potentially mitigate these losses, farmers in Northern Ontario, Canada, are incorporating woody residues into their soils during conversion to retain more organic matter on-site, while bringing the land into production faster than conventional conversion approaches. The current study examines the effects of converting forest to agricultural land on soil by comparing SOC storage in the top 45 cm of mineral soil in forests, old (> 50 year) and young (< 10y) conventionally cleared fields, and young fields with mulched forest biomass incorporated into the soil following land clearing in the Great Clay Belt, northeastern Ontario, Canada. There were no statistically significant effects (<i>p</i> > 0.05) of land conversion on SOC storage but there was a redistribution of SOC with depth consistent with soil tillage. Observed trends in mean SOC storage suggest that incorporating woody mulch residues into the soil at the time of conversion may warrant further study as a SOC conservation strategy.</p>","PeriodicalId":520462,"journal":{"name":"Discover soil","volume":"3 1","pages":"45"},"PeriodicalIF":0.0,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13098991/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147794795","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Soil CO₂ and CH₄ response to experimental warming under various tree species compositions in a temperate harwood forest.","authors":"Sharlène Laberge, Blandine Courcot, Rolando Trejo-Pérez, Nicolas Bélanger","doi":"10.1007/s44378-025-00045-4","DOIUrl":"10.1007/s44378-025-00045-4","url":null,"abstract":"<p><p>Under climate change, some forest ecosystems appear to be transitioning into net source of carbon dioxide (CO₂), raising questions about the future role of soil respiration rate (R_s), which depends on hydroclimatic conditions. Conversely, well-drained forest soils could become more significant sinks of methane (CH₄) under warming. The main objective of this study was to assess the effects of artificial soil warming on R_s and CH₄ fluxes in a sugar maple forest at the northern limit of Quebec temperate deciduous forests in eastern Canada, and to evaluate the effect of species composition on soil response to warming. We measured R_s and CH₄ fluxes during the snow-free period of 2021 and 2022 in 32 plots distributed across three forest types, half of which were artificially heated by approximately 2 °C with heating cables. Forest soils were a very consistent sink for CH₄ and it did not respond to artificial soil warming nor was it sensitive to variations in soil moisture, ionic activity in soil solution and forest types. However, we observed an increase in R_s in response to warming in the heated plots, but only up to a threshold of about 15 °C, beyond which R_s started to slow down in respect to the control plots. We also observed a weakening of the exponential relationship between R_s and soil temperature beyond this threshold. This trend varied across the forest types, with hardwood-beech stands being more sensitive to warming than mixedwoods and other hardwoods. This greater response of hardwood-beech stands to warming resulted in a more significant downshift of R_s, starting from a colder temperature threshold, around 10-12 °C. This study highlights a potential plateauing of R_s despite rising soil temperature, at least in eastern Canada's temperate deciduous forest, but this trend could vary from one forest type to another.</p><p><strong>Supplementary information: </strong>The online version contains supplementary material available at 10.1007/s44378-025-00045-4.</p>","PeriodicalId":520462,"journal":{"name":"Discover soil","volume":"2 1","pages":"21"},"PeriodicalIF":0.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11912556/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143653274","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}